Safety guard



sept. 4, 1923. l1,467,186

J. C. MERWIN SAFETY GUARD Filed March 2o. 1922 2 sheets-sheet 1 Filed March' 20,"1922 2 Sheets-Sheet 2 UNITED `[SFMES PATENT OFFICE-if JOH-N CLIFFORD MERWIN, OF MILWAUKEE, WISCONSIN, ASSIGNOR T'O CHAIN Patented Sept. 4, 1923.

COMPANY, OF MILWAUKEE, WISCONSIN, A CORPORATION -OF WISCONSIN.

SAFETY GUARD.

Application led March ,20, 1922. 'Serial` No. 545,130.

T0 all whom t may concern: l

Be it knownthat I, JOHN CLiFFoRD lMER*- WIN, a citizen of the United States, residing at Milwaukee, in they county of` Milwaukee and State of Wisconsin, have invented certain new and vuseful Improvements in Safety Guards, of which the following is a specification. y I f In many concrete `mixers* particularly thoseof large size and such as are constructed for use inv paving operationsfit is customary to dump the `solid ingredients that enterA into a single fcharge offthe mixer into a loading skip, that is connected with the framework surrounding themixer and is arranged to be lifted` and vtilted, so that its charge will slide'orspill `into the .mixing drum. After being thusemptied it is returned to the ground to vreceive the ingredients of another charge which are commonly dumped into it from trucks, loadingibuckets, or barrows. When the loading skip is in its elevated and charging position it is high above-the ground, and it is common practice to return it to its lower position to receive the next charge rapidly. It valso sometimes happens that a skip will fall from its elevatedl position through breakage of parts or other; accidental reason. The falling of a charging skip,V and even its return to its lowermost position under normal working conditions, are vattended with moreor less danger toworkmen whoA may carelessly pass. under the skip whenraised, for it is a large and ponderous`,obje,ct,k and since itv moves in descending with much rapidity a blow therefrom liable to be attended with serious results.

lMy inventionhas for'its object to Apr A`vide such a loading skipv or. other analogous mechanical device, withLY a guard. that'fautomatically comes .intoposition topreventk a person passing below-j the rsk-ip orgother ,device when raised. t

In the accompanying drawings I=i1lus trate the invention applied to a lconcrete mixingmachine. i l Figure 1 isa side elevation vof a machine embodying my invention, showing theloading skip inits lowermost position ,by'full `lines and in its elevated position by"r dotted mes. v 4

Fig. 2 is a side view of a dierentiembodiment of the invention. 1

Fig. 3 is a plan view of the fguard de-l tached from the mixingmachine;

In the drawings, 2 yindicates a"mixin`g drum, and 3 the framework/surrounding"it, of a portable concrete 'mixing machinel such as is used in paving-operations. 1:* f"

4 lndicates the loading skip,` adapted when in its lowermost lposition'," sh'owi'rin full lines, to rest upon the 'ground so that-it may be loaded by hand from wheelfbarrows,

or from a truck backedv up to the end of the.J

since it is well known in the.artQand forms r no partV of the presentfinvent'ion The skips controlling mechanism so' far as 'f fk-.shown comprises pulleysf 18 over whichy pass Vfthe cables 5,*the small'pulleys lor ,drums 19l upon which the lcables are wound, and thejlager drum 2O constituting a pai-tof -theQcable winding 'and controlling `'mechanism.v In the formr of, invention represented inj Figi "l cured fast to itslspout end/'and vpivotalllyV lunitedmwith `Vthe".framework V3 at'.7. 'i The parts thus lfar described are' A'all Awell known construction... f

A guard to-serve as awarningi'ot tY bnter the'- space below the charging when it is in its elevated-position,is,snpported by the lframeworkdof 7the mixingma'chine and vit is adaptedto..besupported,at a suitable height` above .the surface .of the)I ground below the skip. :Y Thisfguard y consists of a pair.. of longitudinal [bars 8,4V Svandfa cross ,ber @meeting theek-@wher .dS-

The inner ends of the bars 8 are pivoted, at l0, to some convenient part of the framework of the machine, as for instance. to the longitudinal sills ll. The distance between the bars 8, 8 is preferably such that they lie comparatively close to the sides of the skip when the latter is in its lower position. rIhe bars may be straight and parallel or they may be fashioned to follow the outlines of the sides of the skip, as may be desired, this being a matter of construction not pertaining to the invention.

They are preferably of such length that the cross bar 9 lies under the bottom of the skip near its front edge when `the skip is lowered, as shown in Fig. l.

rIhe guard has combined with it means that cause it to maintain the desired extended position above the surface of the ground and beneath the skip when the latter is raised.. In `practice it extends out from its pivotal supports 10 substantially horizontally and' is about three vfeet from the surface of the ground.

Various means may be employedffor controlling the-.movements of the guard. For instance, in the form ofinvention shown in Fig. Q, springs l2, onenear each pivot l0,

act on' theguard and lift it to -zguarding position when free to do so. The bars 8 are extended beyond the pivots 10, to form short arms 13, and these, in the form of invention shown in.-Fig. 2, are.A adapted to engage with .stopslicarried bythe sills ll to arrest the guard when the springshave lifted it to the desired position to act as a barrier and warning to persons moving'in the vicinity of the mixer. .As theV skip descends it falls between the side bars 8 and its bottom comes intocontact with the cross bar 9 andcarriesthe guard downward along with the descending skip yto the position indicated in. Figs. lv and '3. y

In F ig. 2 the skip vdoes not havethe pivot bars 6 but carries perforatedlugs-Qt by which it may be pivotally connected with the'. framework of thev mixer, an arrangement that is to be preferred in some types of mixing machinesito that illustrated in In the yform of invention illustrated in Fig. `lthe short angularly arranged.Y arms li'of the side bars S are connectedby links l5 with 1 arms or cranksl 16 extending radially from the pivots 7. vvThe arms 16 may be secured fast either lto the pivot bars ,(5 orl to thev pivotwpins. T, the important, feature being [that- .thev crank arms move synchronously Vwith the movements of the charging'spout and preferably about the same axis. TheA relative lengths. ofy the crank ,arms 16 and the arms 1.3 are such that while the charging skip moves from the lowermost'position shown in'ffull lines to its upper discharging position, the guard moves a much less distance, from the full line position to that represented in dotted lines.

`While the two sets of operating means shown for causing the movements of the guard are both practical, other means for effecting the movements described may be employed, since the invention is not limited to the specific means that may be used for effecting the movements described.

It will bc seen that the guard innowise interferes with the operation of the skip. lhen the latter is in its lower position to `be loaded the guard lies close alongside the skip with its cross bar 9 under the .door of the skip and doesknot interfere with the movements of the wheel barrows or other instruments employed in loading.

The guard described may be cheaply manufactured and easily applied to machines that are already in use as well as to new machines as part of their original equipment.

That I claim is:

l. The combination with a pivoted'skip and means for raising and lowering it, of a guard supported adjacent to the skip and means for moving the latter to `a protective position above the surface of the ground and below the skip when the latter is raised.

2. 'I`he combination with a loading skip and means for elevating it for the purposes of discharge and lowering it to the ground where it may be loaded, of a guard for enclosing the space below the skip when it is raised, andmeans operating when the skip is elevated to move the guard to position between the surface of the ground and the skip. f

3. The combinationv with a loading skip and means for controlling its movements while being elevated and lowered, of a guard arranged when the skip is lowered to beA engaged thereby and moved toward the surface of the earth, and means for lifting the guard when the skip is raised to position to discharge. g

4. The combination with a loading skip, a support by Awhich it is carried and means for controlling its movements while .it is being elevated and lowered, of guard supported by the. said support and. arranged to surround the space below the skip when the latter is elevated and sopreventpersons passing under the skip, and'means forraising the guard into operative position when the skip is raised and for movingr it into such position that itshall notr interfere with the loading of thel skip when the latteris lowered.

5. fThe combination with a loading skip. means for controlling its movements while being elevated and lowered, and a supporting frame by which the skip is carried, of a guard supported by the said frame and comprising a pair of side bars and a cross bar,

the latter being adapted to lie between the bottom of the skip and the ground when the skip is lowered, and means for raising the guard when the skip is raised so that it encloses the space below the skip.

6. The combination with a loading skip and means for controlling its movements while being elevated and lowered, of a pivoted guard enclosing a space below the skip when elevated, and means connected with the skip for operating the guard arranged to lift the latter to a position above the surface of the ground when the skip is raised, and to lower the guard when the skip is lowered.

7. The combination with a pivoted loading skip and means for controlling its move-V 

